Went to the dyno today to see what I picked up on the dyno after the HKS install and I only picked up 5 HP and 4 TQ Peak at the wheels. I was 10 degrees hotter from my last dyno but I doubt that made a difference. I will post dynos later. I probably need a UTEC.

 

Did you lose any low end torque?

 

Ouch...But what can we say, the stock exhaust is pretty d*mn good . i barely felt anything in the butt dyno with my nismo exhaust

 

Exhaust systems are mainly for BLING purposes on Zs LOL. Unless you go turbo. I would be glad to gain anything really.

 

That's about right. Unfortunately our motor does not respond to bolt ons like a Corvette.

 

+1, exactly. MFG's claim big numbers, but most exhaust systems offer little to no gains.

 

Yes a little bit.

 

with all after market exhaust, you ONLY expect gain from 4 to 8 max, if lucky, you will get 10. HKS is more for look. That is one of the reason why i change my mind at the last min before cough out $1300+ for it.

 

Test pipes will gain you much more relatively speaking. Exhaust is a sound mod really when it comes to n/a.

 

Doesnt Import Tuner magazine claim on their dyno pages that the HKS hi power can produce 11-14 rwhp?

 

Yep.

 

i think most of us here want to go with HKS because the look and the sound. If i buy it, i don't expect much hp gain though.

 

Yes you are correct. The main reasons to go with this exhaust would be for sound, weight loss, looks, and compatibility with TT's.

 

Whats your afr?

Getting HFC or Test Pipes will give you more gain, as the stock cats are very restrictive, so you don't benefit too much from just an exhaust when everything still needs to pass through the very restrictive stock cats to get to the exhaust.

+1 On the exhaust being mostly for looks and sound. Most aftermarket exhauts give close to the same gains, thats why the major factor that I considered when buying it was looks and sound.

Also, if your not planning on going with FI soon, a blue e-manage or eu can do the job of fine tuning your car just as well as the utec.

 

Gains are pretty much the same from most aftermarket exhausts, the major difference on the market is sound and looks.

I dont expect many extra ponnies from just swapping the exhaust, i got the HKS for the sound and looks. I hope to feel atleast a little more power on the butt dyno with headers and the HKS though, but not expecting a lot.

My focus is the overall feeling and sensation of driving dynamics, engine sound is a key element in achiving what im after. No matter how good the car is, if it sounds like crap i will never really enjoy driving it, even a car which dosent go very well can still be very engaging to drive if it sounds good

/Roger

 

I didn't have my AFR measured. What is the difference in the E-manage and UTEC? Also do you know that the price difference is?

 

Here is the dyno. Bottom line is the stock dyno with no mods and the top line is the dyno run with the MREV and HKS.

 

has anyone ever weighed the stock exhaust system from the headers or cats back? I wonder how much weight would be saved by going with test pipes, and a JIC single exhaust?

 

The UTEC has more options such as better timing control. However, when your N/A, all you really need to do is fix the afr. The blue e-manage or the e-manage ultimate can do the job just fine. The UTEC costs about $900 (thats the lowest I've seen), the e-manage blue costs about $300, and the e-manage ultimate costs about $500. The e-manage blue and e-manage ultimate are not plug and play, and installation can take up to 3-4, while the UTEC is plug and play and I've heard shops only charge an hour for it. The only difference between the e-manage ultimate and UTEC is that with the UTEC you have real time timing, and with the EU you don't. Thats what I've read on this board. Supposedly, Greddy will soon realease new software updates that will enable the EU of real time timing.

I've persoanally seen N/A cars gain about 10rwhp from a tune with the e-manage blue, and I've read on the board about N/A cars gaining 10rwhp from a tune with the UTEC. It all depends on the tuner I guess, but I personally wouldn't spend all the money on the UTEC if I was N/A. I wouldn't go any higher than the e-manage ultimate.

 

Well, our stock exhaust (without the cats) weighs 70lbs. I didn't weigh the stock cats, but one of the stock cats was much heavier than both of my resonated test pipes.